CAISO has been exploring ways to deal with that problem. One of the solutions on the table, termed "load consumption," was to incentivize the consumption of more electricity during periods of high renewable energy generation — "paid to wastefully consume energy," as CAISO put it.

But CAISO stakeholders such as Tesla, Stem and Green Charge Networks argued in favor of an alternative storage product that would shift peak solar output by absorbing peak energy and storing it for later use.

In a presentation, John Goodin, manager of infrastructure and regulatory policy for CAISO, said a "load shift" product would ensure excess power is "used productively at a different time to the benefit of the economy and environment" and would "avoid increasing the economy’s energy intensity."

The proposed load-shifting product falls under the third phase of CAISO’s Energy Storage Distributed Energy Resource (ESDER) program. The proposal is still in its early stages and will require several rounds of comment before it is sent for approval by the California Public Utilities Commission and the Federal Energy Regulatory Commission.